Phase transitions of aqueous solutions of charged polymers and proteins have been reported. See Wei, W.; Waite, J. H. et al., A mussel-derived one component adhesive coacervate. Acta Biomater 2014, 10 (4), 1663-1670; Ahn, B. K.; Das; Lipshutz, B. H.; Israelachvili, J. N.; Waite, J. H. et al., High-performance mussel-inspired adhesives of reduced complexity. Nat Commun, 2015, 6; J. N.; Waite, J. H.; Ahn, B. K. et al., Microphase Behavior and Enhanced Wet-Cohesion of Synthetic Copolyampholytes Inspired by a Mussel Foot Protein. J Am Chem Soc, 2015, 137 (29), 9214-9217; Brangwynne, C. P. et al., Polymer physics of intracellular phase transitions. Nat Phys, 2015, 11 (11), 899-904. Cation-π interaction is strong in aqueous media and may be used for wet-adhesion in biology. See Lu, Q., et al., Adhesion of mussel foot proteins to different substrate surfaces. Journal of the Royal Society Interface, 2013, 10 (79).